This invention relates to a hanger system which is employed to suspend a tubing string in a well in the ocean floor, a running tool employed with the tubing hanger, and a method preferably associated with the tubing hanger and the running tool. More particularly, this invention relates to a nonorienting hydraulic set tubing hanger and a nonorienting hydraulic set running tool employed for running, landing, locking, sealing, and retrieving the tubing hanger.
In oil well applications, various devices and methods have been advanced for suspending strings of tubing from a tubing hanger which is seated on a subsea casing hanger in a subsea wellhead housing. Various running tools, including hydraulically actuated tools, have been developed for "running" the tubing hanger to the wellhead, locking the tubing hanger to the wellhead or casing hanger, sealing the tubing hanger to the wellhead or casing hanger, and retrieving the tubing hanger form the wellhead. Exemplary prior art tubing hangers and/or running tools for subsea oil well drilling operations are disclosed in U.S. Pat. No. 3,693,714 for "Tubing Hanger Orienting Apparatus and Pressure Energized Sealing Device," U.S. Pat. No. 3,688,841 for "Orienting Tubing Hanger Apparatus," U.S. Pat. No. 3,807,497 for "Orienting Tubing Hanger Apparatus Through Side Pocket Mandrels Can Pass," and U.S. Pat. No. 4,067,062 for "Hydraulic Set Tubing Hanger." Previous tubing hangers generally required means for angularly orienting the tubing hanger with the wellhead, the guidance system, and/or the running tool. Moreover, the operational mode of prior tubing hangers, as exemplified by the above-referenced patents, typically requires that the tubing hanger essentially be retrieved as a unit and does not allow for separate retrieval or the sealing unit of the hanger.